trsv

Solves a system of linear equations whose coefficients are in a triangular matrix.

Description

The trsv routines compute a matrix-vector product with a triangular band matrix. The operation is defined as

op(A)*x = b

where:

  • op(A) is one of op(A) = A, or op(A) = AT, or op(A) = AH,

  • A is an n-by-n unit or non-unit, upper or lower triangular matrix,

  • b and x are vectors of length n.

API

Syntax

void trsv(queue &exec_queue,
     uplo upper_lower,
     transpose trans,
     diag unit_nonunit,
     std::int64_t n,
     std::int64_t k,
     buffer<T,1> &a,
     std::int64_t lda,
     buffer<T,1> &x,
     std::int64_t incx)

trsv supports the following precisions and devices.

T

Devices Supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

std::complex<float>

Host, CPU, and GPU

std::complex<double>

Host, CPU, and GPU

Input Parameters

exec_queue

The queue where the routine should be executed.

upper_lower

Specifies whether A is upper or lower triangular. See Data Types for more details.

trans

Specifies op(A), the transposition operation applied to A. See Data Types for more details.

unit_nonunit

Specifies whether the matrix A is unit triangular or not. See Data Types for more details.

n

Numbers of rows and columns of A. Must be at least zero.

a

Buffer holding input matrix A. Must have size at least lda*n. See Matrix and Vector Storage for more details.

lda

Leading dimension of matrix A. Must be at least n, and positive.

x

Buffer holding the n-element right-hand side vector b. The buffer must be of size at least (1 + (n - 1)*abs(incx)). See Matrix and Vector Storage for more details.

incx

Stride of vector x.

Output Parameters

x

Buffer holding the solution vector x.